[alexw]

I wanted to switch out my cable and discovered this. The connectors with the black stuff were very hard to pull apart. I carefully tried to pick some of it out with a plastic toothpick, and it came out in small amounts. I tried to get some decent shots of it. What is this? If you need better pictures, please tell me and I'll try to get them.
 

 

 

[Dulalala]

It's probably oxidization I would just get some alcohol, tissue and a toothpick and clean it off.